The present invention relates generally to switched communications networks using Common Channel Signaling (CCS) and more particularly relates to a system, method and apparatus for monitoring and testing the operation of the CCS network.
One system for providing a Common Channel Signaling Network (CCSN) utilizes Signaling System 7 (SS7) protocol in a Packet Switched Data Network (PSDN) connecting Network Elements (NE) via packet switched 56 KB digital data circuits. In addition to providing call set signaling functions, the SS7 network also provides access to switching control points (SCP) used to permit line identification database (LIDB) queries for credit card verification and 800 database look-up for 800 services. Class services also use the SS7 network to provide custom call features. The latest services using the SS7 network comprise Advanced Intelligent Network (AIN) services. AIN services use the SS7 network to access an Integrated Switching Control Point (ISCP) where AIN service functions are performed.
This network currently employs various Network Traffic Management (NTM) and NE test and provisioning systems to maintain the NEs in the Public Switched Network. However, these systems can only report troubles and provide manual NE trouble resolution tools. The Bellcore SS7 Engineering and Administration System (SEAS) was developed to provide Network Management functions for the SS7 network, but lacks the ability to anticipate troubles and provide corrective action instructions to NE operations personnel. Also, both NTMs and SEAS use information supplied from the NEs or the SS7 switching transfer point (STP) hardware which, when in trouble, can often cannot provide timely status information to maintenance personnel because of excessive NE and STP processor demands. SS7 STPs are especially susceptible to processor delays due to the extremely high volume of SS7MSUs generated and processed during a major trouble condition. For these reasons an SS7 Real Time Monitoring System (RTMS) which is outside of the STP environment is needed to maintain the SS7 network and to ensure SS7 network reliability.
Current telecommunications and data networks using CCS generally utilize the protocol of Specification of Signaling System 7 (SS7) which is described in Section 6.5, LSSGR, Issue 2, July 1987, TR-TSY-000506, a module of TR-TSY-000064. Various methods and techniques for testing and analyzing the operation of such networks have been proposed including, by way of example, in co-pending application Ser. No. 07/953,173, filed Sep. 29, 1992, and commonly assigned with the present invention. Generally speaking, such prior arrangements for testing of SS7 networks have been responsive to malfunctions or else conducted on a routine basis at periodic intervals. Such techniques, while effective for their intended purposes, offer little, if any, assistance in detecting incipient developing problems so rapidly as to permit and provide prevention of network failure before the development of the problem is complete.
Accordingly it is an object of the present invention to provide a communications network preventative maintenance tool that detects potential CCS and switched network troubles, automatically analyzes such troubles and provides corrective action or instructions in time to avoid major breakdown.
It is another object of the invention to provide an SS7 Real Time Monitoring System (RTMS) which is outside of the STP environment and has the ability to anticipate troubles and provide corrective action instructions on a sufficiently rapid basis to detect incipient problems and provide corrective action before a serious network problem develops.
The SS7 Real Time Monitor System of the invention is a multi stage SS7 network preventative maintenance tool that detects potential SS7 and switched network troubles, automatically analyzes these troubles, and provides alarm and corrective action instructions to maintenance personnel in time to avoid a major network event. This is accomplished by placing real time SS7 monitors on links at the Signal Transfer Points (STPs). Information on exceeded Link Load, exceeded Message Signaling Unit (MSU) frequency and Network Management status/error conditions is passed to a Stage 1 controller or process. The Stage 1 process controls link monitors capable of monitoring upwards of 32 link monitors at a single STP. The monitors perform preliminary link analysis on error conditions. If the monitors identify trouble on any of the links, alarm information is sent to a Stage 2 controller or process via the Stage 1 process. The Stage 2 process controls all Stage 1 and associated monitors from an STP pair. If Stage 2 determines that there is an STP pair network trouble, it generates alarm and corrective action information and passes it to the Stage 3 controller or process. The Stage 3 process controls all Stage 2 controllers or processes in the operating company. If Stage 3 determines that there is potential or real company network trouble, it generates alarm and corrective action information and display signals on maintenance terminals in the company""s SS7 control center (SEAC, SCC, etc.). Stage 3 also alerts the Stage 4 controller process.
The Stage 4 process is connected to all Stage 3 processes in the Region. It receives alarm/alert and corrective action information from the Stage 3 processes. It analyzes this data and determines if a similar trouble could happen in another company""s network. The Stage 4 process informs the affected company""s Stage 3 processes that a potential trouble condition may exist in their network. It will also pass along or generate corrective action/trouble verification information relevant to their network configuration.
These four controllers and processes provide a means to achieve a real time SS7 network maintenance/management system capable of preventing major company and Regional SS7 failures. The Stage 5 process is an interface to the Company""s Network Surveillance System (NSS). This interface allows the Stage 3 and Stage 4 processes to get STP status information needed to assist trouble analysis. Also, since the SS7 Real Time Monitor System is capable of identifying troubles in seconds, it can pass alarm and status messages to the NSS system. The NSS system can use this information to anticipate Central Office (CO) alarms and ignore those alarms that it already knows will be generated. This allows the NSS system to concentrate its efforts on fixing the troubles at the CO and working interactively with the SS7 Real Time Monitor System to correct any remaining troubles.